Which one? That’s the question we always have to ask unless someone is so specific as to answer the question before we ask it. When we already had a Washington, District of Columbia, why would we name a state Washington as well? If we’re telling someone about Nebraska, all we have to say is Nebraska and we’re done. If we say Washington, then we have to say Washington, the state, not Washington, D.C., or vice versa.
Not an efficient use of language.